Impact switch



April 10, 1956 E. D. RICHARD 2,741,674

IMPACT SWITCH Filed Sept. 29, 1954 INVENTOR Eugene 0. Richard ATTORNEYS States ate .1

United States of America as represented by the Secretary of the Army Application September 29, 1954, Serial No. 459,221 2 Claims. (Cl. ZOO-61.45) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to electrical switches for grenade fuzes and more particularly to the improved construction of switches adapted to function a grenade fuze on impact with a target regardless of the orientation of the switch with respect to the target when impact occurs.

One object of this invention is an impact switch which can be quickly and easily assembled by unskilled workers.

Another object of the invention is a switch which is self aligning in assembly and which maintains that alignment after assembly.

Another object of the invention is the assembly of two subassemblies wherein each subassembly acts as a guide for the other subassembly.

A further object of the invention is an impact switch which is inexpensive to manufacture.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from the following description and drawings wherein:

Figure 1 is an exploded perspective view of the invention, partly in section.

Figure 2 is an elevational view of the switch, partly in section.

Figure 3 is a perspective view of the contact elements of the switch.

The switch comprises two identical assemblies indicated generally by numerals and 10a, Fig. 1. Each assembly comprises identical nonconductive body portion 11, central contact 12, and a plurality of contact fingers 13 disposed about central contact 12 and depending from collar 19. Central contact 12 is located within cavity 14 of body portion 11 and is atfixed to wall 15 of the body portion. The neck 16 of central contact 12 extends through aperture 17 in wall 15 and is peeued over washer 18 to secure the central contact to the body portion. Collar 19 separates central contact 12 from wall 15.

The body portion of assemblies 10 and 10a indicated generally by numeral 11 is of irregular shape as seen in Figs. 1 and 2 and comprises radially cut away guides 20 and depending feelers 21 spaced therebetween. In the preferred embodiment of the invention each body portion has four cut away guides and four depending feelers in spaced relationship with one another and with the four contact fingers of each assembly. When the two assemblies are fitted together each depending feeler 21 of one assembly is guided into place within a single cut away guide 20 of the body portion of the other assembly. When the two assemblies are fitted together as seen in Fig. 2 two series of apertures 22 are formed therebetween. The apertures are directed inwardly at an angle of forty-five degrees with the longitudinal axis of the switch and are partly closed at their inner ends by contact fingers 13. Fingers 13 are biased outwardly and against the inner surface 23 of body portion 11. The contact fingers of one assembly are adjacent to but out of contact with the central contact 12 of the other assembly. The contact fingers 13 of one assembly are in interdigitated relationship with the contact fingers 13 Egg of the other assembly and forty-five degrees out of phase therewith.

Into apertures 22 are placed ball Weights 24, one within each said aperture. A nonconductive outer case 25 is positioned about the assembled switch. Ball weights 24 are constrained within apertures 22 by said outer case and by contact fingers 13.

The switch is closed by an acceleration or deceleration of sufiicient magnitude applied in any direction. Contact fingers 13 are adapted to bend inwardly when subjected to a predetermined force. The force employed is the inertia force of the ball weights when the grenade in which the switch is employed impacts with a target. At least one ball weight 24 moves against its associated contact finger 13 to move the contact finger inwardly. When contact finger 13 of one assembly engages central contact 12 of the other assembly, the grenade fuze circuit is completed and the fuze functions to cause the grenade to detonate.

It will be apparent that the embodiment shown is only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as defined in the appended claims.

I claim:

1. An impact switch comprising a first assembly having a nonconductive body portion and a contact portion, the said contact portion comprising a central contact and a plurality of contact fingers disposed about and biased outwardly of said central contact; a second assembly identical to the first assembly, the two assemblies being adapted to slide together, the body portion of the first assembly adapted to guide the second assembly into axial and rotational alignment with the first assembly and the body portion of the second assembly adapted to guide the first assembly into axial and rotational alignment with the second assembly, the engagement of the two assemblies being such that the contact fingers of the first assembly are adjacent to the central contact of the second assembly but out of contact therewith, and the con tact fingers of the second assembly are adjacent to the central contact of the first assembly but out of contact therewith, the one set of contact fingers of said first assembly being in interdigitated relationship with the contact fingers of said second assembly and forty-five degrees out of phase therewith, the engagement of the two body portions forming therebetween two series of apertures, each aperture being adjacent one contact finger and adapted to contain a single ball weight therein; and an outer case enclosing the assembled switch, the said ball weights being constrained in said apertures by said outer case and by said contact fingers, the arrangement of the switch being such that, when subjected to a force or acceleration in excess of a predetermined minimum, at least one ball weight, by inertia, will move against its adjacent contact finger to move the said contact finger into contact with its adjacent central contact and close the switch circuit.

2. The invention in accordance with claim 1 wherein each body member is provided with radially spaced cut away guides and depending feelers therebetween, each cut away guide of the body member of the first assembly adapted to receive a single feeler of the body member of the second assembly, and each cut away guide of the body member of the second assembly adapted to receive a single feeler of the body member of the first assembly, the feelers of one body member being in interdigitated relationship with the feelers of the other body member and in contact therewith, the two body members when assembled together forming therebetween two series of apertures, each aperture adapted to contain a single ball weight No references cited. 

